Help with a Byrne's Saw - end of cut problem

[rtropp]

Hi,

I have been using my Byrnes saw to cut strips, mostly 1/14, 1/16, 3/32.  The strips are coming out spot on to measurement.  Never having used a table saw of any type before, this was pretty surprising.  Its really nice to be able to rip strips as I need them.  No worry about running out, especially nice with all the rework I do.

 

Anyway,

I was ripping a few different strips from Basswood. One example of the sheet was a 1/4 by 4" by 24" from which I cut an 11/32" wide strip.

 

For almost all the strips, when I get about 4-6" from the end of the 24", The blade starts to catch, burn the wood a little and the wood struggles to get through the cut. I make sure the wood is firmly held flat at the blade towards the feed side. 

 

I have added a prop behind the saw that prevents the ends from sagging, at it helped a little, but I still get the wood catching in the blade.

 

I would appreciate any suggestions.

 

Richard 

[DaveF]

  It doesn't matter size of saw the result is the same. Your wood is binding or twisting at the end of your cut.

 Questions to ask.

 Are you using a push stick to move the wood through at end of cut? Important for fingers but twisting occurs.

 Are you making sure wood is up against fence at all times? It is natural to concentrate on the blade ( because that's where the cutting is )

 

 Burning is usually a sign of misalignment as wood passes between blade and fence.

 Also check that fence is absolutely parallel to blade. Any misalignment ( .oo1 to .005 on the smaller saws will cause this).

 How about blade rotation alignment. As the blade turns does it have a wobble. Put a mark on the flat area of the blade close to a tooth. Now put a dial indicator guage at the mark. Rotate the blade by hand. ( unplugged). If the blade has a wobble by more than .003 you will need to shim at the blade hole and arbor to correct.

 Hope this will help.

 BTW. Over the years if my saws are heavily used, like ripping a lot of stock, I constantly check the above 1 a month.

 Dave

[russ]

I would contact Jim Byrnes about your problem and get his advice.

 

Russ

[AntonyUK]

Hi Richard.

When pushing through make sure the push stick in between the blade and the fence.

Pushing from the none fence side will cause the timber to jam on the blade.

The fence will hold the timber true but as the cut is coming to the end the push will close the Kerf.

 

Can do a drawing better to explame what I am talking about.

 

Regards Antony.

[Landlubber Mike]

I had a similar problem on my Byrnes saw.  New to table saws, I couldn't figure it out so I spoke with Jim.  He suggested when tightening down the fence, to push the rear of the fence slightly away from the blade when tightening it down.  That seems to have helped my problem.

[Richard Griffith]

Richard and others, it sounds like the blade is heating up and warping before you get to the end of your cut.  When this happens, you will get burning and binding.  It is not the table saw per se, unless the table top is misaligned or your fence is bent.

Some items to do:

1. put in a blade with fewer teeth or with larger gullets

2. use a blade with more set (teeth that are wider than the blade)

3. slow down the rate at which you push the wood thru the blade. 

 

If you still get binding, stop the cut and let the blade cool down. 

Pushing the rear of the fence a couple of thousands away from the blade is an excellent idea in nearly all cases. 

 

Remember, the thinner the wood, the more teeth you should use.

 

Hope this helps, let us know how you make out.                                          Duff

[Boatsinc2000]

Hi Richard,

 

Causes:  The issue is that the wood is moving on you and touching the back portion of the blade.  This is caused by releasing the internal stresses in the sheet and you may even see the material moving towards the blade (gap created by the blade kerf is narrowing towards the back side of the cut).  Not so much with basswood, but there also can be changes in the direction of the grain that will cause the same issue.  Some blades that are too thin or dull will follow the grain and you can see that the piece that you are cutting is actually getting wider as you cut and consequently binding.  Seems as though the thicker the stock and the wider the piece that you are cutting, the more that you will see this issue.  Refer to the last page on my website regarding use of a Byrnes saw.

 

Solutions:

 

1)  Use your .040 kerf blade instead of your .030 kerf blade.  (thicker kerf tends to reduce binding and blade deflection)

 

2)  Add back taper on fence.  Start with adding .005, then add another .005, if necessary.  This will have a big impact on this problem

 

3)  Turn piece end over end.  This changes the direction of the grain of the wood and helps if the blade is following the grain instead of release of stress in the wood.  Usually not an issue with basswood, unless your blade is dull.

 

4)  Try cutting from the other side of the piece or go to a different sheet all together.

 

5)  Change saw blade to new sharp saw blade.  Probably not needed in this case unless you have been using it for really hard exotics like ebony or bloodwood.  Once I use a blade on those woods, I do not use it again on my regular stock such as cherry, box, pear, or holly.

 

Richard, I hope the above is helpful.  In the end #2 will help the most because with these slitting blades the teeth and the body of the blade are essentially the same kerf.  Using a carbide blade will also eliminate the problem because the teeth are a wider kerf than the body of the blade and that provides additional clearance..

 

This is a common issue, so you are not alone.  It all has to do with using the slitting blades instead of a carbide tipped blade.

 

Cheers,

 

Jeff

HobbyMill

[gjdale]

Having had the same issues and having tried all of the advice above, including an email discussion with Jeff Hayes, I decided to try adding an extra piece of fence to the front half of the high fence. I used some aluminium flat bar, drilled and tapped some holes in the existing high fence and screwed it on. The additional fence extends from the front of the table to approx the centre of the saw blade. The theory is that this will allow extra clearance on the back half of the blade, without the need to offset the rear of the fence, which should make setup a lot simpler. I discussed this with Jeff before leaping in, and he agreed with my theory. I've yet to have a chance to test the completed modified fence, but will post here when I do if that will help folks.

[rtropp]

guys,

I really appreciate all your thoughts.  I have made a list of the ideas and will begin by pushing the end of the fence away from the blade about .005.  This seems to be considered the first thing to try and will also be the quickest.  If that doesn't help I will keep going down the list to see what helps.

 

I'll let you all know the results as I get a chance to test them.  

 

Thanks to all.

 

Richard 

[ChadB]

I'll second Landlubber Mike's fix... I just switched to a slitting blade like Jeff mentioned on the Hobbymill site and had the saw bogging down once wood (pear- 1/4) got thru to the rear of the blade. I started tightening the front of the fence and giving the rear a tiny nudge outward, and that did the trick. No effect on thickness.  -Chad

[gjdale]

Just following up on my post of 08 Jun and my solution to the problem of blade binding while ripping strips. I said that I had added an extra piece of fence to the front half of the high fence, extending from the front of the table to approximately the centre of the saw blade, with the theory being that this would allow extra clearance at the back of the blade to prevent the binding issue without having to try and offset the rear of the fence.  Well, I've since tested this and it works like a charm.  Here's a few pics of my setup - very simple, and quite crude, but effective. I've set the blade (a 0.04" kerf) at max height for the photos, but of course that is adjusted to a suitable height for the thickness of the material being cut.   

 

 

 

 

 

Being attached with only two screws, it is quite simple to remove when it's not needed, and very quick to install when it is.

 

I've also invested in a set of Ripping Gauges from Micromark.  These are inexpensive, work very well and make setting up for a "standard" size cut very simple and, more importantly, repeatable.

 

 

Hope this is of some help to those who may have experienced similar problems with ripping stock.

[mtaylor]

I like that setup.   Did you tap the fence or is there nut/washer inside the fence?    You got me thinking of something like that for my MicroMark saw.

[gjdale]

Mark - I drilled and tapped the fence.  Of course, this was the first time I had ever tried tapping and didn't watch the YouTube "how to" until after I had broken several taps - hence the few 'extra' holes you can see (evidence of broken off taps stuck in the fence!).

 

A key point to keep in mind is that the screws need to be countersunk into the attachment so that a flush face still remains on the business side of the fence.  This means that the material used for the attachment needs to be of sufficient thickness to allow the screw head to be countersunk.